In this study, nano-sized powder of Ni-ferrite was fabricated by spray pyrolysis process using the Fe-Ni complex waste acid solution generated during the shadow mask processing. The average particle size of the produced powder was below 100 nm. The effects of the reaction temperature, the inlet speed of solution and the air pressure on the properties of powder were studied. As the reaction temperature increased from 80 to 110, the average particle size of the powder increased from 40 nm to 100 nm, the fraction of the Ni-ferrite phase was also on the rise, and the surface area of the powder was greatly reduced. As the inlet speed of solution increased from 2 cc/min. to 10 cc/min., the average particle size of the powder greatly increased, and the fraction of the Ni-ferrite phase was on the rise. As the inlet speed of solution increased to 100 cc/min., the average particle size of the powder decreased slightly and the distribution of the particle size appeared more irregular. Along with the increase of the inlet speed of solution more than 10 cc/min., the fraction of the Ni-ferrite phase was decreased. As the air pressure increased up to 1 , the average particle size of the powder and the fraction of the Ni-ferrite phase was almost constant. In case of 3 air pressure, the average particle size of the powder and the fraction of the Ni-ferrite phase remarkably decreased.

본 연구는 재래산양의 핵이식을 실시하여 공여세포의 조건, 전기적 세기 및 융합횟수 등이 융합율과 체외발달율에 미치는 영향을 조사하여 최적의 융합조건을 확립하고자 실시하였다. 공여세포는 귀 유래 섬유아세포와 태아 유래 섬유아세포 2종류를 분리 배양하여 사용하였으며, 수핵란의 채취는 성숙한 미경산 재래산양에 과배란을 유기하여 hCG 투여 후 제 35시간째에 외과적인 방법으로 in vivo (체내성숙)난자는 난관을 관류하는 방법으로 회수하고 in vitro (체외성숙)난자는 난포로부터 흡입하여 난포란을 채취하여 약 22시간 체외성숙을 실시하였다. 수핵난자는 난구세포를 제거한 다음 0.05 M sucrose를 처리하여 세포질이 양호하고 극체가 뚜렷하게 보이는 난자만을 선별하여 핵이식을 실시하였다. 핵이식란의 융합은 전기자극방법으로 융합을 실시하였으며, 핵이식 조작 후 약 3시간 동안 전배양을 실시한 다음 활성화를 유도하였다. 복제수정란은 0.8% BSA가 첨가된 mSOF 배양액으로 6∼7일 동안 체외 배양을 실시하였다. 귀 유래 섬유아세포를 공여세포로 사용하였을 때 융합율은 60.4%로서 태아 유래 섬유아세포의 40.3%보다는 높게 나타났다. 분할율에 있어서는 귀 유래 섬유아세포와 태아 유래 섬유아세포가 각각 47.6 및 48.2%로서 차이가 없었다. 2.40∼2.46 ㎸/㎝로 전기자극을 주었을 때 융합율은 43.8%로서 1.30∼l.40 ㎸/㎝(26.7%)와 2.30∼2.39 ㎸/㎝ (34.8%)가 높게 나타났으며, 융합이 이루어진 핵이식란의 분할율은 82.9(1.30∼l.40 ㎸/㎝), 43.8(2.30∼2.39 ㎸/㎝) 및 51.8%(2.40∼2.46 ㎸/㎝)로서 전기자극의 세기에 따른 유의적(p＜0.05)인 차이는 없었다. 전기융합을 1회 실시하였을 때 in vivo 난자는 43.5%로서 in vitro 난자의 23.6%보다 유의적으로 높게 나타났으며, 2회 실시하였을 때는 55.7(in vivo) 및 39.2%(in vitro)로 in vivo에서 높게 나타났다. 3회 자극을 주어 전체 융합율은 in vivo가 66.1%로서 in vitro의 52.8%보다는 유의적으로 높게 나타났다.

Effects of liquid phase and reinforcing particle morphology on the sintering of Al-6 wt％Cu-10 vol％ or SiC particles were studied in regards to densification, structure and transverse rupture properties. The Al-Cu liquid phase penetrated the boundaries between the aluminum matrix powders and the interfaces with reinforcing particles as well, indicating a good wettability to the powders. This enhanced the densification during sintering and the resulting strength and ductility. Since most of the copper added, however, was dissolved in the liquid phase and formed a brittle phase upon cooling rather than alloyed with the aluminum matrix, the strengthening effect by the copper was not fully realized. Reinforcing particles of agglomerate type were found less suitable for the liquid phase sintering than solid type particles. and SiC particles protluced little difference on the sintering behavior but their size had a large effect. Repressing of the sintered composites increased density and bending properties but caused debonding at the matrix-particle interfaces and also fracturing of the particles.

This study carried out a questionnaire survey of opticians working at optical dispensing shops and eye elinies in Seoul and Gyeonggi-do for their job satisfaction for the period from june to October 2003. According to the result of analyzing opticians' job satisfaction according to their general characteristics, job satisfaction appeared higher in those aged over 36, in married ones than unmarried ones, and in college graduates and above. In addition, job satisfaction was higher in those working at ophthalmologic hospitals than those working at optical dispensing shops, in managers than in employees, those with a monthly salary over 3 million won, those who work less than 8 hours a day on the average, and those who have work experience over 8 years. However, no significant difference was found according to gender and the number of job changes. According to the result of regression analysis on general characteristics and job satisfaction, influence was high in order of working hours a day, workplace, academic qualification and location. According to the result of analyzing the 7 factors of job satisfaction, which were autonomy in work, human relations, work environment, occupational pride, job status, wage and the sense of belonging, opticians generally appeared to be satisfied with autonomy in work, human relations, job status and the sense of belonging, but not in work environment, occupational pride and wage. In addition, according to the result of comparing opticians working at optical dispensing shops with those at ophthalmologic hospitals for the 7 factors, the latter were more satisfied than the former in human relations, work environment, occupational pride and job status.

점박이응애(Tetranychus urticae)에 대한 34종 terpene의 훈증독성, 접촉독성 및 기피효과를 조사하였다. 훈증독성은 10/1(공기)의 농도에서 isosafrole, safrole이 모두 98.4%의 살비율을 나타내었다. 이 두 화합물의 LD값은 각각 2.6, 4.3/1이었다. 접촉독은 isosafrole만이 알에 대해서 60.2%의 살란활성을 보인 것 외에 대부분의 terpene에서 활성이 낮거나 없었다. 약제감수성 계통에 대한 기피반응을 조사한 결과 hexanoic acid와 limonene이 1,000ppm에서 각각 79.1%와 87.8%의 기피효과를 나타내었다. 한편 fenprothion저항성 계통과 pyridaben저항성계통에 대해서 hexanoic acid는 각각 77.8%과 83.3%의 기피효과를 나타내었다. 그러나 두저항성계통에 대한 limonene(1,000ppm)의 기피효과는 각각 17.8%와 10.0%로서 감수성계통에 대한 기피효과와 상반된 결과를 나타내었다.다.

The trends in building construction these days are moving towards having better work space and greater suitability for the use of information technology, Therefore people can work in a more relaxed, delightful and pleasant environment. So accidents like fire could cause the mass destruction of human beings. In this paper, we estimated the escape time from a building and simulated the study results on computer to see how safe it would be in a real situation.